In recent years, coating of a DLC film on a machine part has been performed with the aim of securing machine part hardness and improving abrasion resistance. Further, in order to improve a mold release property of a mold, coating of a DLC film on a mold has been also performed, and thus the DLC film has been used variously.
It has been generally known that when a DLC film is film-formed on the surface of a base material, the DLC film becomes likely to peel off because adhesiveness between the base material and the DLC film is bad. Therefore, forming an intermediate layer between the base material and the DLC film has been performed with the aim of improving the adhesiveness between the base material and the DLC film conventionally. For example, Patent Document 1 discloses a method of film-forming a Ti layer and a TiC layer as an intermediate layer. By providing the intermediate layer between the base material and the DLC film as above, the adhesiveness between the base material and the DLC film is increased.